Then communicate with your healers. I've played healers although not in end-game raiding, and I usually will just throw a regen if I see a DPS about to take damage. I don't care if you're trying to "maximize efficiency" or just being dumb, because there's no way to tell. But if the hit is going to be a big one, or if it is part of mechanics (as opposed to randomly targeted damage), then I will Rescue if I happen to be within range.
You cannot expect healers to read your mind. The annoying obstacle is the lack of communication.